Influence of different atria types on energy efficiency and thermal comfort of square 

plan high­rise buildings in semi­arid climate

Jaberansari, M and Elkadi, HA

Title Influence of different atria types on energy efficiency and thermal comfort of square plan high­rise buildings in semi­arid climate

Authors Jaberansari, M and Elkadi, HA

Type Conference or Workshop Item

URL This version is available at: http://usir.salford.ac.uk/39262/

Published Date 2016

USIR is a digital collection of the research output of the University of Salford. Where copyright permits, full text material held in the repository is made freely available online and can be read, downloaded and copied for non­commercial private study or research purposes. Please check the manuscript for any further copyright restrictions.

For more information, including our policy and submission procedure, pleasecontact the Repository Team at: usir@salford.ac.uk.

International conference on Energy, Environment and Economics, 16-18 August 2016

Page 1

Influence of different atria types on energy efficiency and thermal

comfort of square plan high-rise buildings in semi-arid climate

Marveh Jaberansari*a, Hisham Elkadib

a,b School of Built Environment, UK

a,b University of Salford, UK

*Corresponding author’s mail: marveh594@yahoo.com, m.jaberansari@edu.salford,ac,uk

Abstract

Building sector is responsible for at least 40% of energy use globally in both developed or developing countries such as the

middle east region (UNEP, 2009) (Francesca Cappellettia et al., 2015) and almost 33% of its energy is known to be used by

HVAC systems in buildings (Salib and Wood, 2013). Iran is one of the developing countries. Even though buildings in Iran also

are accounted of 40% of all energy used in the region (Mahdavinejad,….) but compared to European countries the building sector

consumes six times more energy (Asgar, 2014).Amongst all building types, tall buildings use more energy due to deep plans and

provision of HVAC to maintain comfort levels (Holford and Hunt, 2003). This building looks into tall buildings and specifically

in office types where more people are allocated in limited space and hence demand more energy. However, the region has a

tradition of successful climatic conscious design solutions such as courtyards hence the paper aims to investigate the impacts of

applying the traditional layout of courtyards to contemporary tall buildings in the form of atria in the semi- arid climate of Middle

East. Cubic shapes are the most common used building forms amongst high-rise buildings in the world (Alaghmandan et al.,

2014), therefore, this paper looks into the square plan shape tall office buildings with no HVAC. Moreover, it provides insight of

the differences in energy consumption to maintain comfort levels of different atria layouts in tall office buildings with a square

plan shape. Dynamic Thermal Simulation (DTS) tool called Design Builder has been used to achieve the target. The software provides results of the prototypes over an annual period of time and compares then with non-atria building.

Keywords: Atrium; office; high-rise; heating and cooling load; energy consumption; thermal comfort

1. Introduction

Because of the rapid speed of population growth in urban

areas and limited land in it, high-rise buildings have emerged

as solution. They allow more people by square meter of a land

compared to low rise buildings (Sauerbruch et al., 2011).

Among other advantages is that high-rise structures compared

to low-rise structures create less carbon footprint (Sauerbruch

et al., 2011) as well as use less material needed for usable

floor space and can reduce energy loads (Sobek, 2011) via the

share of natural energy between floors (Salib and Wood,

2013).

However, Tall buildings tend to have an energivore due to

deep plans and especially provision of Heating ventilating and

air conditioning (HVAC), to maintain comfort levels (Holford

and Hunt, 2003). Using HVAC as a mean to assist thermal

comfort has resulted in 33% of energy usage in commercial

and office blocks around the world (Salib and Wood, 2013).

So the amount of energy used to provide thermal comfort

mechanically is considerable. Not designing buildings

according to climate conditions results in consuming a lot of

energy and money (Wahid, 2012). Thermal comfort is one of

the most important parameters when designing buildings

(Douvlou (2003) and when buildings are designed poorly it

leaves no choice but to reply on mechanical means, HVAC, for

providing one of the basic needs of human beings: thermal

comfort for occupants Wahid (2012).

Therefore it is of much importance to try to achieve the

thermal comfort via natural means as much as possible and to

lower the energy usage in buildings via incorporating energy

efficient strategies into designs (Aldawoud, 2013). There are

other advantages in providing heating and cooling via natural

means (Douvlou, 2003, Abdullah, 2007, Health and Saftey

Executive, 2014):

Reducing resource depletion

Reducing harmful impacts to environment because of

pollutions caused by energy production

Reducing costs

Reducing Sick Building Syndromes (SBS)

International conference on Energy, Environment and Economics, 16-18 August 2016

Page 2

Improvement of human productivity because of

healthier environment

This paper explores the performance of tall offices in

Tehran. The climate in Tehran is semi-arid climate, which has

hot summers and cold winters. Achieving thermal comfort

range naturally for the occupant of a building throughout the

year is a challenge in the semi-arid climate which has hot

summers and snowy winters. The semi-arid climate of Tehran

is one example which has this characteristic.

However it is not an impossible task as vernacular

architecture of the semi-arid climate of the region in middle-

east, has successful designs which used passive ways to

provide inhabitants with a comfort temperature inside houses.

One interesting passive strategy used is that of including

courtyards. Courtyards have been used in different climate

zones because they are actually energy efficient in all climates

(Aldawoud and Clark, 2008).

2. Atria

Atrium is derived from the Latin word “āter” which means

“Dark” and refers to a central space open to the sky and

surrounded by rooms that used to be covered with dark black

smoked walls in traditional houses of Rome (Moosavi et al.,

2014) (Fig 1). The idea of atrium was partially inspired by

courtyards, an old tactic for climate control (Abel, 2000, Medi,

2010). Bednar (1986) believes that the history of atria is

known to have begun with the archaeological remains of

Ur.Mesopotamia, a Malaysian courtyard house, in 3000 BC

and that later on the central uncovered roof houses were found

in ancient Greek and Roman cities, where the open space

allowed fire smokes to escape and allow daylight in. It is then

believed that this form was extended in the middle-east

forming a larger courtyard space (Sharples and R.Bensalem,

2001) (Fig 2). During the late 19th century and the beginning

of 20th century the traditional forms of courtyards gave its

place to the atrium enclosures in buildings (Abel, 2010).

Gradually atrium was introduced into office spaces in early

20th century (Abel, 2010) and by late 1950’s and early 1960’s

modern atria were gradually becoming common (Atif, 1994) .

Fig 1: Section of typical Persian house with courtyard and wind

catcher in the Middle-East.

Atria are mostly popular with large office headquarters as well

as commercial buildings and shopping malls (Reid et al.,

1994). The popularity of atria in office towers became even

more since SOM (Skidmore, Ownings and Merrill LLP)

architects, Norman Foster and Ken Yeang led the way (Abel,

2010). However, many large office blocks were using atria as

a central open courts or light wells in the 19th century when

there was actually more advantages to it (Salib and Wood

(2013). In fact buildings are still using atria mainly as means

for circulation purposes (Sharples and R.Bensalem, 2001).

It can be argued that atria with or without a roof in high-rise

buildings are somehow the extrusion of courtyards in low rise

buildings and can also be a potential strategy for providing

thermal comfort in buildings with less energy consumption

that one without an atrium. Hence, atria do have the potential

to provide occupants comfort through solar radiation and

natural heating and cooling in order to minimize lighting,

heating and cooling energy requirements (Abdullah, 2007).

Some of the potential advantages of Atria are:

Providing Natural Ventilation: Moosavi et al. (2014)

strongly states that “Natural ventilation is the main

potential environmental advantage of atria”.

Providing Natural light: Atrificial lighting is known

to be the major element that contribuets a great deal

in increasing heating loads (Aldawoud, 2013) and so

atrium would be huge bonus in this aspect especially

in deep plan public buildings.

Providing solar gain: The sun rays can provide heat

in this space (Assadi et al., 2011, Abdullah and

Wang, 2012) and the heat can be captured

Provide better air quality: By using plant-filled

atrium, air could be filtered and particulates removed

when it enters the hollow space (Barkkume, 2007).

Provides Shelter: A buffer zone sheltering the space

form wind , snow rain and other outdoor

environmental factors while retaining the outdoor

effects such as fresh air, natural light and sunshine

(Göçer et al., 2006)

Provides great visual space: (A.Lauouadi et al., 2003)

Provide social gathering and circulation area as well

as green space (bryn1993;bednar,1986; saxon 1986)

and (Gocer, Tavil, 2006) and (Moosavi et al., 2014)

also consider atrium having significant impact on

increasing inhabitants socialization and interaction.

3. Project statement

Even though HVAC, supposes 33% of usage in tall

commercial and office blocks, at times it could be the only

remaining solution in constructions especially commercial

towers where there is a greater size of floor area, higher

population density and internal heat gains through equipment

(Salib and Wood, 2013). However, noticing that atrium is

International conference on Energy, Environment and Economics, 16-18 August 2016

Page 3

becoming a very popular feature of large buildings (Assadi et

al., 2011) because of its various advantages, it is of importance

to optimize the atria design and to ensure it is not poorly used,

in order to maximize using passive heating and cooling as

much as possible before using HVAC.

Some examples of office buildings having atria to assist

bringing down energy consumptions of HVAC are

Commerzbank Tower in a temperate climate of Frankfort,

Torre Cube in humid climate of Guadalajara and St.Mary Axe

building in temperate climate of London which they have

80%, 100% and 40% naturally ventilation throughout the year

respectively (Salib and Wood, 2013, Jenkins, 2009, Wells,

2005).

However, this paper presents preliminary results of Dynamic

thermal simulation in semi-arid climate and compare the

influence of different atria types on office heating and cooling

hours in a typical high-rise building and to compare it also

with a base study of office high-rise building with no atria.

This paper also identifies which types of atria and which

orientation are beneficial in this climate.

4. Basic Atria Configuration

The placement of the atria is the main factor determining

the advantages that an atria could potentially have in a

building (Moosavi et al., 2014). Out of nine classified generic

types of atria (Saxon,…), five types have been recognized as

the simpler forms suitable for buildings whether it be small or

complex (Fig 2):

Single sided (ex: Law Courts, Vancouver)

Two sided atrium (ex: Ford Foundation, New York)

Three sided atrium (ex: Hercules plaza, Wilmington)

Four sided or central atrium (ex: IMF headquarters)

Linear atrium (ex: Hennepin County)

Fig 2: Five basic configurations of atria in buildings (Onyenobi,

2008)

Central atria, similar to central courtyard in plan, is the most

common form of atria and used normally in deep plan office

buildings to allow natural light into the centre (REF?). Linear

atria also allows air and light deep into the plans of a deep

plan building. Moreover, single sided atria have been used

usually in temperate climate as a glazed façade in order to

have more solar heat gains in winter time as well as great

views during the rest of the year, while linear and central atria

seem to be used mostly in hot and humid climate (Moosavi et

al., 2014)

Fig. 3: plan shapes of 73 tallest buildings in the world

(Onyenobi, 2008)

Architectural shapes of most high-rise in the world have

been derived from basic forms which are square, triangle and

circle (Onyenobi, 2008) .Figure 3 compares plan shapes of 73

tallest buildings in the world; it could be seen that rectangular

and square shape buildings have been and still are amongst the

most used building shapes (Alaghmandan et al., 2014). Thus

this study only focuses on the square shape high-rise office

buildings with the previous 5 different types of atria.

Computer simulation is used to predict the (thermal)

performance of buildings at sketch stage design (Clarke,

2001). Predicting early results of projects that could inform

future action or research in the real world (Wang and Groat,

2002) is very important as it prevents problems early in the

production process rather than later finding and fixing them

which causes other problems in itself ie. cost (McLead, 2001).

It also allows a great number of possibilities to be tried in a

short space of time (Malama, 1997). Computer simulation is

also used for the development of this prototype.

5. Preliminaries

This research is conducted in the city of Tehran with

average low and high daily temperatures ranging from -5 to 40

during a year (fig 4).

International conference on Energy, Environment and Economics, 16-18 August 2016

Page 4

Fig. 4 Tehran temperatures graph produced by climate

consultant software

According to literature review and Tehran regulations of

high-rise buildings, the typical high-rise prototypes is a

minimum of 12 story height with 500 m2 office area on each

floor and 500 m2 of atria plan area, 40% external window to

façade ratio, 60% of internal window to façade ratio, with atria

roof opened in hot days and closed in cold days (BHRC,

2007)(Göçer et al., 2006, BHRC, 2014, TMPD, 2012).

Fig. 5: main prototype cases

Thermal simulation has been carried out in Design-

builder software which uses Energy Plus. The prototypes are

run on office hour times and Natural ventilation mode is set to

“ON” which means that the external and internal windows to

open if set point temperatures are met.

The minimum set point temperatures that closes the

external windows is 21 °C, which is within the comfort

temperature in cold seasons and because outdoor temperature

of hot seasons does not reach 21 during working hours of the

day therefore it is a reasonable figure.

It is also important to know that the thermal comfort

range in Tehran climate according to Heidari (2009) survey in

Tehran and his produced formula, ranges from around 18 °C to

26.5°C in cool season and from around 23.5°C to 31.5°C in

warm season. Thus any temperature outside these ranges in

cool and warm seasons is classified as cold or hot

uncomfortable temperatures and therefore the hours are

counted as hours which are need of mechanical heating or

cooling. (have to rephrase the last 2 paragraphs)

6. Results and discussions

Five types of atria (Fig 5), have been designed into square

plan shape prototype buildings, all with the same fixed floor

atria plan area. The prototypes have gone under simulation

with the consideration of four main orientations in two sets of

simulation of warm season and cold season. So for example if

the atria was 1 sided and faced towards the south it is called a

1 sided south atria. Overall a number of 64 simulations were

run on prototypes.

The results of cold hours (hours below 18°C) are in fig 7

and hot hours (hours above 31°C) are in fig 6.

Fig. 6

Fig. 7

As it can be seen in summer base case scenario which has

no atria performs better. Because the amount of hours above

comfort range in a building with no atria is 4537 which

International conference on Energy, Environment and Economics, 16-18 August 2016

Page 5

compared to all other options in atria is the least amount. This

is possible as Bednar (1986) and Zhang (2009) explain that the

atrium can be a direct heat gain space which might be of

advantage in winter but can be a disadvantage in summer as

well. Fig 8 below also shows that the base case has the least

amount of heat gains via windows compared to other

prototypes. Apart from central atria, other prototypes do have

a 100% atria glazed façade towards outside meaning that their

external glazing to façade ratio increases which adds to the

heat gains via external windows (included in the solar gain

exterior window graph in figure 8) which explains why the

heat gains are more.

Fig 8 solar gains warm season

Never the less, there are other sources of heat gains in

offices such as computer and equipment heats, occupants,

windows and heat from light bulbs (fig 9). Which explains

even though the heat loss in base case with no atrium is the

least (fig 10) , however, since the heat gain is also small

compared to other prototypes, thus it still remains the best

option in summer hot days, having the least amount of

uncomfortable hours.

Fig 9 heat gains in warm season

fig 10: heat loss warm season

However, the situation is very different is cold days.

Because the solar gains are more in 1 sided atria compared to

other atria and in fact the base case is the worst case scenario.

Again apart from central atria, other prototypes do have a

100% atria glazed façade towards outside meaning that their

external glazing to façade ratio increases which adds to the

heat gains via external windows (included in the solar gain

exterior window graph 11) which explains why the heat gains

are more some atria rather than others and the base case.

Fig 11 solar gains cold season

Fig 12 Heat gains cold season

In winter the atria cases which are the coolest result in

more cold uncomfortable hours for occupants in offices, and

the greenhouse effect of atria are favourable in this situation.

Hawkes and Baker (1983) states that in cold climates using

closed top glazed atria are obviously beneficial as they can act

as a buffer zone between indoor environment and harsh

external climate condition and be used as means to reserve

heat during sunny days of cold climates and helping with the

heating load. Bednar (1986) and Zhang (2009) also explain

that the atrium can be a direct heat gain space because of its

greenhouse effect which is the effect when short waves enters

the atrium, hits the face of objects, transforms into long waves

and ultimately gets trap in a closed atria

International conference on Energy, Environment and Economics, 16-18 August 2016

Page 6

Fig 13

Overall, the annual uncomfortable hours in a 1 sided atria

facing west is less than other types and orientations of atria

and most certainly is the better option than not having atria at

all in semi- arid climate (fig 13).

Fig 14: annual heating and cooling loads

Also from fig 14 above it can be seen that the heat load is

considerably more than cooling load and so it is important to

provide heat via natural means in cold days as much as

possible.

7. Conclusions

It is of much importance to minimize the energy

consumption in buildings. This paper shows the consumption

between high-rise office buildings without atria and those

high-rise buildings with other different types of atria. The

results confirm that using atria and one which faces the west,

for office hours in a semi-arid climate can contribute towards

lowering the annual energy loads which in return lowers the

energy consumption to provide thermal comfort temperature

in office buildings of semi-arid climate.

8. References

A.LAUOUADI, M.R. ATIF & A.GALASIU 2003. Methodology towards

developing skylight design tools for thermal and energy

performance of atriums in cold climates. Building and

Environment, 38, 117-127.

ABDULLAH, A. H. 2007. A Study on Thermal Environmental Performance in

Atria in the Tropics with Special Reference to Malaysia. PhD,

Heriot-Watt University.

ABDULLAH, A. H. & WANG, F. 2012. Design and low energy ventilation

solutions for atria in the tropics. Sustainable Cities and Society, 2, 8-

28.

ABEL, C. 2000. Prime Objects. Archietctural Design, Building Case study. 2

ed.: Archietcture & Identity.

ABEL, C. 2010. The vertical Garden City: Towards a New Urban Topology.

CTBUH Journal, 20-25.

ALAGHMANDAN, M., BAHRAMI, P. & ELNIMEIRI, M. 2014. The Future

Trend of Architectural Form and Structural System in High-Rise

Buildings. Architectural Research, 4, 55-62.

ALDAWOUD, A. 2013. The influence of the atrium geometry on the building

energy performance. energy and Buildings, 57, 1-5.

ALDAWOUD, A. & CLARK, R. 2008. Comparative analysis of energy

performance between courtyard and atrium in buildings. Energy

and Buildings, 40, 209-214.

ASGAR, M. G. 2014. Reviewing challenges and techniques of using energy in

iran health system. Indian Journal of Fundamental and Applied Life

Sciences 4, 1646-1650.

ASSADI, M. K., DALIR, F. & HAMIDI, A. A. 2011. Analytical model of

atrium for heating and ventilating and institutional building

naturally. Energy and Buildings, 43, 2595-2601.

ATIF, M. 1994. Top glazed public spaces, Amenities, Energy, Costs and indoor

enviroment,. Construction canada, 36, 43-47.

BARKKUME, A. 2007. Innovative Building Skins: Double Glass Wall

Ventilated Façade. 1-26.

BEDNAR, M. J. 1986. The new atrium, London, Mc Graw Hill.

BHRC 2014. Section 4: General Building Requirments. Iranian National

Building Regulation. Tehran: Building and Housing Research

Centre.

CHING, F. D. K. 2007. Architecture: Form, Space and Order, New Jersey, John

Wiley & Sons.

CLARKE, J. A. 2001. Energy Simulation in Building Design, Oxford,

Butterworth-Heinemann.

International conference on Energy, Environment and Economics, 16-18 August 2016

Page 7

DOUVLOU, E. 2003. Climatic Responsive Design & Occupant Comfort: The

Case Of The Atrium Building In A Mediterranean Climate. PhD.,

The University of Sheffield.

FRANCESCA CAPPELLETTIA, TIZIANO DALLA MORAA, FABIO

PERONA, PIERCARLO ROMAGNONIA & PAOLO

RUGGERIA. Building renovation: which kind of guidelines could

be proposed for policy makers and professional owners? . 6th

International Building Physics Conference, IBPC 2015 2015.

Energy Procedia, 1-6.

GÖÇER, Ö., TAVIL, A. & ÖZKAN, E. THERMAL PERFORMANCE

SIMULATION OF AN ATRIUM BUILDING. IBPSA

International Building Performance Simulation Association of

Canada’s biennial conference., 2006 Canada. E Sim.

HAWKES, D. & BAKER, N. 1983. Atria and Conservatories. The architects

Journal, May, 18 &24.

HEALTH AND SAFTEY EXECUTIVE. 2014. Thermal Comfort [Online].

Health and Saftey Executive (HSE). Available:

http://www.hse.gov.uk/temperature/thermal/index.htm.

HEIDARI, S. 2009. Comfort Temperature of Iranian People in City of Tehran.

Honar-Ha-Ye-Ziba: Memary Va Shahrsazi 1, 5-14.

HOLFORD, J. M. & HUNT, G. R. 2003. Fundamental atrium design for

natural ventilation. Building and Environment, 38, 409-426.

JENKINS, D. 2009. Swiss Re Headquarters. Norman Foster Works 5. Prestel:

Munich.

MALAMA, A. 1997. Thermal comfort and thermal performance of traditional

and contemporary housing in zambia. PhD, Sheffield University.

MCLEAD, P. 2001. The Availability and Capabilities of 'Low End' Virtual

Modelling (prototyping) Products to Enable Designers and Engineers

to Prove Concept Early in the Design Cycle, Loughborough, Pera

Knowledge.

MEDI, H. Field Study on Passive Performance of Atrium Offices: case study

in semi arid climate. 1st International graduate research

symposium in the built enviroment, 2010 Ankara, Turkey. METU

(Middle East Technical University), 1-7.

MOOSAVI, L., MAYHYUDDIN, N., GHARFAR, N. & ISMAIL, M. 2014.

Thermal performance of atria: an overview of natural ventilation

effective designs. Renewable and Sustainable Energy Reviews, 34,

654-670.

ONYENOBI, T. 2008. Impact of high-rise morphology on gas temperatures

during fire. PhD, University of Salford.

REID, G., LINGSEY, B., EMOND, D., BATTLE, G., GRANGE, S. &

HAWKES, D. 1994. Cambridge calling- building study. The G.

Architects, 29-36.

SALIB, R. & WOOD, A. 2013. Natural ventilation in high-rise office buildings,

New york, Routledge.

SAUERBRUCH, M., HUTTON, L. & HINTERTHAN, A. 2011. CTBUH

Interviews – 2011 Awards Symposium. CTBUH.

SHARPLES, S. & R.BENSALEM 2001. Airflow in courtyard and atrium

buildings in the urban enviroment: a wind tunnel study. Solar

Energy, 70, 237-244.

SOBEK, W. 2011. CTBUH Interviews – 2011 Awards Symposium. CTBUH.

TMPD 2012. New Terms and Conditions of Detailed design Tehran. In:

DEPARTMENT, T. M. A. P. (ed.). Tehran: TMPD.

UNEP 2009. Building and Climate Change: summary for decision-makers. In:

BRANCH, U. D. S. C. P. & INITIATIVE, S. B. C. (eds.). France:

United Nations Environment Programme (UNEP).

WAHID, A. 2012. Adaptive vernacular options for sustainable architecture.

ISVS, 2, 74-87.

WANG, D. & GROAT, L. 2002. Simulation and Modelling Research. In:

WANG, D. & GROAT, L. (eds.) Architectural Research Methods.

Canada: John Wiley & Sons, Inc.

WELLS, M. 2005. Skyscrapers : structure and design, London, Laurence King.

ZHANG, A. 2009. Sustainable atrium a landscape design. MSc., Univeristy of

Sheffield.